I have tried adding parenthesis to the code but lindo gives an error stating that its a variable. According to lindo documentation "(" should be accepted as a parenthesis but this does not occur. Removing the parenthesis causes the code to terminate as soon as it encounters the division symbol. Does anybody know what I'm missing in my code? (error occurs on the 4th, 5th and 6th line of code).
min Y1 + Y2 + Y3 + Y4 + Y5 + Y6
ST
Y1 + Y2 + Y3 + Y4 + Y5 + Y6 >= 1
5X11 + 10X12 + 2X13 + 5X14 + 4X15 + 4X16 / Y1 <= 10
5X21 + 10X22 + 2X23 + 5X24 + 4X25 + 4X26 / Y2 <= 10
5X31 + 10X32 + 2X33 + 5X34 + 4X35 + 4X36 / Y3 <= 10